Twenty-one years after the 9/11 terror attacks killed almost 3,000 Americans, the wounds wrought by that carnage are still fresh to Bonita Mentis.

Her sister, Shevonne Mentis, 25, was working for a financial firm in the World Trade Center when two of four planes commandeered that morning hit the twin towers. Bonita Mentis, at a commemoration Sunday in New York reading from the list of victims’ names, said she still has the shoes her sister was looking for before leaving for work the morning she died.

“The day I was born I became your sister. The day you died you became my guardian angel,” Mentis said. “We love you, we miss you and we will never forget you.” 

The ceremony at the National September 11 Memorial & Museum was one of many across the nation in remembrance of the attacks that rocked the world. President Biden laid a wreath at the Pentagon and first lady Jill Biden spoke in Shanksville, Pennsylvania. Events at all three sites where the strikes occurred included a reading of the names of those who died.

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Other communities around the country were holding candlelight vigils, interfaith services and other commemorations. Some Americans are joining in volunteer projects on a day that is federally recognized as Patriot Day and a National Day of Service and Remembrance.

President Joe Biden, speaking to a somber crowd in the rain outside the Pentagon, pledged to continue combatting terrorism and called on Americans to stand up for democracy.

“America itself changed that day,” Biden said. “But what we will not change, and never will, is the character of this nation that the terrorist thought they could wound.”

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In Shanksville, the names of the passengers and crew members were read with the ringing of the Bells of Remembrance starting at 10:03 a.m., the moment Flight 93 crashed. The plane went down after passengers and crew members tried to storm the cockpit.